An energy consultant who is one of the Marin Clean Energy Authority's most ardent critics got the chance to make his case against the authority unchallenged at a San Rafael meeting of the Marin Coalition on Wednesday.

"What's behind the green curtain?" asked Jim Phelps of Novato, who has worked as a consultant to the electric and petrochemical industries. "Lots of renewable energy certificates, lots of dirty power."

Dawn Weisz, Marin Clean Energy's executive officer, said, "We asked to be able to participate in dialogue with him today, and we were not allowed to be on the panel."

Basia Crane, a Marin Coalition board member, said no representatives from Marin Clean Energy were invited to participate due to a request from Phelps. The coalition, a community organization that holds forums on topical local issues, may invite a Marin Clean Energy representative to speak at a future meeting, a member said.

The authority, which consists of the county of Marin, all 11 of Marin's municipalities and the city of Richmond, serves as the retail electricity provider for 124,000 customers. The county of Napa and the cities of Albany and San Pablo have asked permission to join the authority, which could add another 27,000 customers. And a group of San Francisco supervisors has expressed interested in having the city, with its 475,000 residential and nonresidential electricity accounts, join the Marin agency.

The authority, which competes with the investor-owned Pacific Gas and Electric Co., was founded primarily to reduce greenhouse gas production by boosting the use of renewable energy sources. Fifty percent of the authority's energy comes from renewable sources, while renewable sources account for 20 percent of PG&E's energy.

Phelps focused his critique on Marin Clean Energy's use of renewable energy certificates, typically referred to as RECs. RECs are tradable commodities that certify that 1 megawatt-hour of electricity has been generated from an eligible renewable energy resource.

"These are just like going to the store buying a loaf of bread and getting a receipt," Phelps said.

He added, "Lots of big companies buy certificates because they feel like it helps the environment. They don't really know what is going on, that's just their own visceral sensibility."

Phelps asserted that clean-energy agencies such as Marin Clean Energy purchase RECs to cloak their use of "system power." He said system power, the mainstay of the electrical grid, consists mainly of energy generated by burning natural gas and coal. That is important because coal and gas produce greenhouse gas emissions, while renewable energy sources don't.

"What happens is they buy a REC, and it is pasted on the front of this brown power," Phelps said. "Then they report to you, the consumers, that this is clean energy; but it's not."

Using this line of argument, Phelps analyzed the Marin authority's power mix substituting system power, which has an emission rate of 944 pounds of carbon dioxide per megawatt hour, for all of the authority's RECs. From that he concluded that Marin Clean Energy is producing more greenhouse gas emissions than PG&E.

"I don't give a hoot about PG&E; I could care less about those guys," Phelps said. "But I've got to talk about them because they're the de facto standard."

Asked about his assertions after the meeting, Weisz said, "The way he has framed his argument is not based on the regulatory environment or the market. It is not based on reality."

According to the federal Environmental Protection Agency, "An organization buying RECs can claim to be buying zero-emission, renewable electricity. RECs and utility green power are fundamentally equivalent environmental products."

And the California Public Utilities Commission, which regulates both PG&E and Marin Clean Energy, states, "A REC represents the environmental and renewable attributes of renewable electricity."

Phelps also criticized the authority for waiting more than a year to purchase 10,500 RECs that reduced its greenhouse gas emission rates in 2011.

Phelps said, "What had happened was MCE's emission rate was higher than PG&E's so they went in the market afterwards and they bought those 10,500 instruments so they could undercut PG&E."

Weisz responded to that issue when Phelps first raised it in December with Marin Supervisor Kathrin Sears, who is on Marin Clean Energy's board.

In a letter, Weisz wrote, "In the simplest of terms, MCE made a commitment to deliver a lower emission factor than PG&E, and that commitment was honored."

Weisz said one reason for the delay was that "large utilities require time to reconcile variations in energy deliveries within a calendar year with usage and to then create accurate reporting."

Phelps, who has written dozens of letters to the Independent Journal criticizing Marin Clean Energy over the past five years, said his wife is jealous of the amount of time he spends on the issue.

He has worked in the past for both PG&E and Shell Energy, one of the authority's major energy suppliers. But he kicked off his talk Wednesday with a disclaimer.

"I'm not here at anybody's behest. I'm not paid or have ever been paid by PG&E for any of the work that I do on community choice aggregation."